Next he should focus on usability and reliability, not more systems. He needs real-time preview syncing, proper rig support (R6, R15, custom rigs), IK/FK controls, curve editor (easing), undo/redo history, autosave and recovery, animation import/export (FBX + Roblox anim IDs), performance optimization for large timelines, and clear UI/UX polish. After that, testing with real animators and fixing workflow pain points matters more than adding new features.